Hydraulic transmission



June 20, E K, ENEDEK HYDRAULIC TRANSMISSION 6 Sheets-Sheetl l Filed May1B, 1935 June 20, 1939. E. K. BENEDEK HYDRAULIC kTRANSMISSION Fi'led May18. 1935 6 Sheet S-Sheet 2 LEK KEIENEEK June 20, 1939- E. K. BENEDEK2,163,079

y HYDRAULIC TRANSMISSION y Filed May 1s, 1955 sheets-sheet :s

T FIEKKEENEDEK 1 1i. f 2 1E E 15H a? En g I June 2o, 1939. E K, BENEDEK2,163,019

June 20, 1939. E. K. BENEDEK 2,163,079

HYDRAULIC TRANSMISSION Filed May 1s, 1955 e sheets-sheet s l is Q l Y/ 7A N LEKKEENEUEK Patented June 20, 1939 UNITED -sTATEs PATENT OFFICE i f2,163,679 HYDRAULIC TRANSMISSION Elek K. Benedek, Bucyrus, OhioApplication May 18, 1935, Serial No. 22,259

18 Claims.

This invention relates to improvements in hydraulic transmissions.Heretofore, in transmissions of this character, wide variation in torqueand speed has been obtained only at a sacrice of eiiiciency and by meansof structures -which are comparatively complicated and expensive and arelarge in proportion to the horsepower output.

The principal object of the present invention is to provide atransmission unit having a much wider range of speed and torque withhigher eniciency throughout the range.

Another object of the present invention is to provide a. multi-stagetransmission in which the various stage units may be adjustedindependently of each other so as to deliver maximum horsepower outputat any speed or torque delivery throughout the entire range and by whichthe transition from one adjusted delivery to another can be eectedsmoothly.

A correlative object is to provide a multi-stage pump and a multi-stage'motor in a combination in which the stage units of each may becontrolled independently1 of the stage units of the other.

A more 'specic object is to provide a compact and simple transmission ofthis character in which the operating parts `are readily accessible forreplacement and repairs and are contained inv a compact casing whichforms part of the operating structure. e

Another specific object is to provide an overrunning clutch connectionbetween barrel portions ofthe respective stages of a pump or motor.

whereby, under certain conditions, each stage can be operatedindependently of the others.

Other objects and advantages will become apparent from thefollowing-specication wherein reference is made to the drawings in whichFig. 1 is a horizontal longitudinal sectional view of la transmissionembodying the principles of the present invention and is taken on theline l-l in Fig. 10;' I

Fig. 2 is a cross sectional view taken on a plane indicated by the line2-2 and 2a-2a respectively in Fig. 1;

Figs. 3 and 4 are sectional views taken on the planes indicated by thelines 3--3 and 4 4, respectively, of Fig. 1;

Fig. 5 is a fragmentary the fluid `outlets of Fig. 4;

Fig. 6 is a fragmentary sectional view illustrating an' overrunningclutch connectionrbetween two adjacent stage units; v

Fig. 7 is a sectional view taken on a plane indicated by the line 1-1inFig. 6;

bottom plan view of tween the cylinders, cylinder ports and valve bore,

and is taken on a plane indicated by the line 9-9 in Fig. 1

Fig. 10 is a side elevation of the `transmission unit illustrated inFig. 1

Fig. 11 is a diagrammatic illustration of the uid circuit of thetransmission illustrated in Fig. 1;

Figs. 12 and 13 are respectively front and side elevations of theplunger and heads illustrated in Fig. 1;

Figs. 14 and 15 are respectively a front elevation, partly in section,and a side elevation, of a slightly modied plunger and plunger headarrangement, the sectional portion of Fig. 14 being taken on the linel4l4 of Fig. 15;

Fig. 1'6 is a plan view of the plunger head illustrated in Fig. 15;

. Fig. 17 is a side elevation of the plunger proper of Figs. 14 and 15;

Figs. 18 and 19 are respectively a fragmentary end elevation andvertical .section of the larger barrel portion illustrated in Fig. 6,showing the coupling;

' Fig. 20 is a diagrammatic illustration of the effect produced in thetiming relation between the pintle ports and cylinders as a result ofwear of the reactance supporting pads;

Fig. 21 is a side elevation of a pintle blank, illustrating the designcharacteristics of the pintle; and

Fig. 22 is a top plan view of a slightly modied form ofthe transmissionillustrated in Fig. 10 enclosed in its supporting casing.

Referring particularly to Figs. 1 to 4, inclusive and Fig. l0, thetransmission is mounted in a rigid load supporting casing I comprising acentral rigid wall portion 2 from which extends, at one end, a largerdiameter annular ange portion 3 and, at the opposite end, a.corresponding annular flange portion 4. The ends of the casing portions3 and 4 are closed by bell-shaped end covers 5 and 6 respectively whichare bolted -to the portions 3 and 4 to provide therewith a rigid unitarystructure in whichvall necessary axial Mounted for rotation within thecasing por,

tion 3 is a pump barrel I0, the barrel being supported at each end inanti-friction thrust bearings I I operating in outer races accuratelytted in the cover 5 and the central wall 2 of the casing respectivelyfor rigidly supporting the barrel for rotation aboutan axis extendingparallel to the axis of the casing. 'I'he barrel is provided midwaybetween the sets of bearings II with a radial flange I2 of properdiameter to terminate radially in inwardly spaced relation from thereactance means, later to be described, so that the reactance means maybe removed axially from the end of the casing without being obstructedby the ange. The barrel is provided With a plurality of radial cylindersI4, in each of which is carried a radially reciprocable plunger I5, theplungers protruding radially of the barrel beyond the cylinder and, attheir outer portions having enlarged heads I6. The heads I6 arereciprocable radially with the associated plungers and operate in radialguideways, I1 formed in the ange I2 and consequently relieve theplungers from torque stresses.

Mounted within the portion 3 of the casing is a stationary reactancemeans, designated gen- .erally as I 8, and comprising an annularreactance housing ring I9 in which are squeeze-fitted parallel, coaxialreactance rings 2U, the rings 20 cooperating with the plungers foractuating the plungers on the pressure strokes consequent upon rotationof the barrel. 'Ihe rings 2U are of hardened, wear resisting metal andare spaced apart axially for snugly receiving between their adjacentradial faces the outermost portions of the heads I5. Y

Inwardly from said portions, each head is provided with a pin receivingbore, extending parallel to the axis of the barrel. Within each bore ismounted a thrust pin 22, each pin 22 protruding parallel to the barrelaxisbeyond the head portion of the associated plunger. The pins 22 aremounted in the heads I6 on capillary cageless anti-friction needlerollers 23, so that the frictional resistance to rotation between thepin 22Y and associated head I6 is less than the rolling frictionimparted to the pin while concurrently adequate bearing contact area towithstand the hydraulic load is provided. On the protruding ends of eachpin 22 are enlarged rollers 24 which are preferably squeeze tted on thepin and form therewith a substantially unitary structure, the rollers 24being in rolling engagement with the rings for transmitting load betweenthe plungers and the reactance rings 20.

In order to actuate the plungers on the suction "strokathrough themedium of the rollers -24 and to retain the rollers in operatingposition relative to the reactance rings 2li, free floating rings 25 areprovided, each ring underlying one set of rollers 24. Due to the factthat the pins 22 are so freely rotatable in the bores of the plungers,free rolling of the rollers 24 is assured so that none of them will tendto drag or slide on the rings 20 or 25 and create .sliding frictionbetween their surfaces and the respective rings.

Instead of the plungers above described, the plungers and heads of Figs.14 to 17 may be used. In this modified structure, the plungers I5 andheads 24' are not connected together but the heads 24 merely abut theouter adjacent ends of the plungers with which associated, which Asidefrom this difference the structure of Figs. 14 to 17 is the same as thatof Figs. 12 and 13 and corresponding parts are equally designated by thesame, but primed, numerals.

The reactance means I8 is mounted for movement to different adjustedpositions in which it is disposed coaxially with or with its axisparallel to but offset from the axis of the barrel. For mounting thereactance means, the housing ring I9 is provided with diametricallyopposite, wide flat slide surfaces 21, and complementary slide surfaces28 are provided on the interior of the casing portion 3 so as to supportthe housing ring I9 for adjustment to different eccentric positions withrespect to the barrel or into position concentric with the barrel. At 90to the planes of the surfaces 21 and 28, complementary diametricallyopposite limit 4abutment surfaces 3l and 32 are provided on the housingring I9 and casing portion 3 respectively at opposite 'sides of thehousing ring I9. Suitable adjusting rods 33, extending radially of thehousing ring I9 and parallel to the abutment surfaces 21 and 28 aremounted in suitable bores in the casing portion 3 and are slidableaxially of the casing bores for shifting the housing ring I9 to adjustedpositions from the outside of the casing. 'I'he rods 33, in turn, may beoperated by any suitable means such as the control set forth in mycopending application, filed October 24, 1934, Serial No. 749,746,issued as Patent No. 2,111,659 on Mar. 22, 1938.

It is highly important that the reactance means be accurately maintainedat all times in its adjusted positions. Since it is subjected to heavyloads and sliding friction on its slide surfaces in the casing portion3, causing wear and resultant inaccuracy, the complementary slidesurfaces of the housing ring I9 and casing portion 3 respectively carryhardened bearing shoes 35. and 36, these shoes being of cyanided or wearresistant material and being readily removable from the housing andcasing for replacement. 'I'he importance of. this feature will beapparent by reference to Figs. 2 and 20.

In Fig. 20, the maximum eccentricity e of the reactance axis is shown asto thev right of the barrel axis O1. The reactance is adjustable alongthe normal line of adjustment N-N, so that' it may be moved the distancee to the right or to the left of O1. Assuming, therefore, that O1, inFig. 20, is the rotational axis of the barrel and O2 and Oz' areexemplary adjusted positions of the axis of the housing ring I9respectively, to maximum eccentricity e and to one half maxlmumeccentricity e/2 it is evident that wearing or misalignment from anycause in the bearings 21 and 28 results in lowering of the axis of thereactance so that the axis of the reactance assumes the positionsindicated by the positions Pz and Pz instead of Oz and Oz. Obviously,this effects 'a downward swing of the normal dead center line ofadjustment N-N through angles and respectively about the axis Ortopositions N' and N". Since the pintle ports, later to be described, arepositioned in a fixed angular rela.- tion to the normal line N to effectproper timing relation with the cylinders in the barrel, this changedposition of the reactance causes a different angular relation betweenthe fixed pintle ports and reactance resulting in undesirableaccelerated or delayed compression and expansion of fluid in thecylinders, evidenced by noise, vibration-and undue wear. y

Since in ordinary usage, the reactances of the motor in the transmissionare shifted more often than that of the pump reactance and are subjectedto greater wear, additional provision 'is made to overcome this wear byproviding antifriction cageless capillary needle rollers between thecasing portion 4 and the motor reactances, as better illustrated in Fig.3.

A valve pintle 40 is rigidly mounted through the medium of a shankportion 40a within the central wall portion 2 of the casing l, andextends from the shank portion 40a axially in opposite directions. Theleft portion of the pintle has a valve portion 4| which snugly fits adead end axial bore in the barrel Ill, the pintle valve portion beingprovided with pressure and suction ports 42,and 43 respectively, each ofthe ports terminating circumferentially of the pintle in slight V-shapednotches, as illustrated, at the ends of the bridge portions 44. Each ofthe cylinders I 4, in turn, opens into the barrel bore in position forvalving cooperation successively with the ports 42 and 43 consequentupon rotation of the barrel, the'passages between the cylinders andbarrel bore preferably being restricted so as to provide greatercircumferential 'clearance between adjacent passages.

In order. to maintain the pintle in accurately centered position withinthe barrelbore and to provide for hydrostatic balance thereof, in themanner set forth in my copending application Ser. No. 754,753, ledNovember 26, 1934, issued as Patent No. 2,126,722 on Aug. 16, 1938,capillary cageless needle rollers 45a and 45h are provided between thepintle and the bore of the barrel l at each end of the valve portion 4iof the pintle. Also, as more fully described in my copending applicationlast referred to, the barrel is preferably counterbored adjacent theshank of the pintle and the pintle is provided with a larger diameterportion disposed therein and cooperat-.

ing with the walls of the counterbore of the barrel through the mediumof the capillary bearings 45b. The pintle pressure ducts, later to bedescribed, which extend longitudinally of the pintle, may be left openat the end of the pintle so as to discharge into the dead end of thebarrel bore for supplying iiuid for hydrostatic bal- 50 is provided withan axial bore-for -rei"."e'iving,A

ance. v

Referring next to the motor of the transmission and the various stageunits thereof, the motor comprises a barrel, designated generally-as 50,which barrel is rotatably mounted near its ends in suitableanti-friction thrust bearings 5| within the casing portion 4 and endcover 6 respectively. The barrel has a larger diameter portion 50a nearthe central wall portion 2 of the casing which portion extends axiallypart way of the length of the barrel and terminates in a reduceddiameter portion 50h, the portion 50h, in turn, extending axially of thebarrel and ter-- minating in an additionally reduced diameter portion50c. In the form illustrated in Fig. 1, all of these portions areintegral, the last portion 56o being provided with the coaxial torquetransmitting shaft 52 of the barrel. Thus the diameter of the barrel issuccessively reduced for each portion from the end adjacent the wallportion 2 of'the casing to the end of the barrel adjacent the shaft 52.

Each of these portions of the barrel 50 comprises a different stage unitof the motor. The units are provided with series of radial cylinders 54,55 and 56 respectively. Likewisethe barrel the corresponding portion ofthe valve "pintle,

the diameter of the axial bore being greater in the unit 50a, of lessdiameter in the unit 50h, and of still less diameter in the unit 50c ofthe barrel. The walls'of all the bore portions are preferably taperedslightly toward the shaft end of the barrel. Likewise the cylinders 54are thelargest pintle are valve portions 60a, 60h and 60o respectively,each being smaller than the preceding in the order enumerated, thesesections of the pintle tting the corresponding bores of the units 50a,50h and 50c. The portions of the pintle are provided with high pressureports 6 la, Gib and Blc respectively and low pressure ports 62a, 62h and62e respectively, corresponding to the stage units, for cooperationsuccessively with the cylinders of the stage units with which associatedfor driving the barrel.A

In the cylinders of the stage units are radially reciprocable plungers,65 and 66 respectively. Since all of the plungers are the same infunction, differing only in size, the plungers 65 of the stage unit 50honly will be referred to in detail. The plungers 65 are provided withhead portions having bores parallel to the barrel axis in which arereceived crosspins 61. Each crosspin is anti-frictionally mounted in itsplunger head bore on capillary cageless needle rollers 68 and providedat its ends with rollers 69. 'I'he plunger heads operate in suitableradial guideways in the ange 10 ofthe portion of the barrel with whichassociated, the iiange 10, in turn, being of less diameter than the loadtransmitting reactances so that the reactances can be removed axiallywithout disturbing the barrel mounting.

The plungers 65 cooperate through the medium of rollers 69 with axiallyspaced coaxial reactance rings 1| arranged in a manner similar to andcooperating with the rollers in the same manner as the reactance ringsof the pump.

The rings 1I are mounted in a reaction housing 12 which conforms inevery way to the reactance housing I9 of the pump except that it ismounted on anti-friction rollers, as better illustrated in Fig. 3.Similarly floating rings 13, comparable to the rings of the pump areprovided, it being noted, however, that the rings 13 i'n the motorportion do not operate the plungers on the low pressure stroke, as thisis unnecessary, but merely serve to retain the assemblies in properoperating positions. If desired, the rings 13and 25 may be split rings,having the usual V-split, as they will be prevented from opening at thesplit by the plunger actuating rollers and are not subject to excessivestresses.

assure free oating action of the rings. The reactance housings of theother stage units are correspondingly mounted on anti-friction rollers.thus reducirig wear and consequent improper synchronization between thepintle' ports and respective cylinders and are diierent in diameter tocorrespond to the difference in: diameter of the units. It will be notedthat the reactance of the motor plungers of-each `unit is disposed inend to end, substantially abutting relation to the reactance and pistonoperating assemblies ofV adjacent stagev units, and Without anyintervening ` Liberal clearance isv allowed between the rings andplunger rollers to supports and with minimum operating clear- 15 ance sothat the axial dimension of the transmission can be reduced as greatlyas possible. The reactance rings of the sets of plungers 64, 85

'and 86 are independent from each other and are mounted in independenthousings, each of which can be adjusted entirely independently of theothers. l

'I'he pintle received in the motor barrel bore is likewise mounted atits ends in capillary cageless needle rollers and 16 respectively so asto\ permit balance of the hydrostatic load on the pintle, as describedin my Patent No. 2,126,722, heretofore referred to in connection withthe pump pintle.

Referring next to the hydraulic circuit utilized in the presentstructure, the pressure port 42 of the pump pintle is connected tolongitudinally extending ducts 88 in the pintle, while the suction port43 of the pump pintle is connected to ducts 8| in the pintle. The ducts88, in turn, communicate with a relief duct 82 provided in the pintleshank 40a. Correspondingly, in the motor end of the pintle are ducts 90which communicate with the high pressure ports Sia, SIb and Sic, andducts 9| which communicate with the low pressure ports 62`a, 62h and 62oof the pintle. The ducts 90, in turn, communicate directly with theducts 80. The ducts 9| communicate with the ducts 8| in a manner to bedescribed, or directly if desired. Thus the pressure port of the pump isconnected to the high pressure port of the rotor and the high pressuremotor ports of the rotor are connected in parallel with respect to eachother. Corresponding'ly, the suction port 43 of the pump and the lowpressure ports 62a, 62h and 62e of the motor are connected in parallelwith each other.

In order to relieve the pressure in case it becomes excessive, the duct82 is closed by a high pressure relief valve 83 mounted in a suitablebore 84 in the wall portion 2 of the transmission casing and seated by aspring 83a. Suitable drain ducts 85 and 86 communicate with the duct 82beyond the valve 83 so that any uid discharged by, virtue of excessivepressure past the valve 83 will be discharged into the interior of thecasing portions 3 and 4.

'Ihe ducts 8| communicate with a duct 8`|` in the wall portion 2 of thecasing which, in turn, communicates with a suitable sump, and the lowpressure ducts 9| communicate with a duct Sia which, in turn,communicates with the same sump. Consequently, an opportunity isafforded to cool the iluid when desired. This relation of the ducts ofthe pump and motor are better illustrated in Fig 11 ,`wherein all of themotor stage units are shown connected" in parallel with each other andwith the pump and a relief valve.

As more fully set forth in my copending application, Serial No. 7,809,filed February 23, 1935, entitled Multi-stage hydraulic pump or motor.and especially with reference to Fig. 8 thereof, greater eiilciency canbe obtained by the utilization of a small pump at high speed than with alarger pump of the same volumetric iluid delivery at lower speed. Again,higher efliciency can be obtained by the use of a motor operating atfull strokethan with a larger motor operating at short stroke but at thesame fluid capacity.

Furthermore, the eillciency of both hydraulic motors and pumps decreasesrapidly as the low eccentricity is approached. As stated, a pump ormotor operating at a given volume at maximum eccentricity is moreeilcient than a large pump or motor operating at less eccentricity butat the same volumetric capacity. Assuming, therefore, that a high speedis required and the pump is operating at full capacity, the stage of themotor unit 58e can be operated. If a less speed is required, unit 5|lbcan be operated, in addition thereto, and if a further speed reductionis desired portion 50a may be operated in addition. Again, if a givenspeed is to be used for a considerable period, all units of the motor,other than a particular one operating, can be set to zero eccentricity.For example, if the large unit at full capacity provides the torquerequired, it

-maybe used alone and operate at its greatest eiliciency and volume, andslowed down by adding the other units. Thus, at all times, the unit orunits can be operated at nearest their full eiliciency and only theexcess over such capacity or speed required is utilized at the lowereiliciency because of a unit operating at less than full stroke. Thusthe fluid discharged from the high delivery pump would not be by-passedand Wasted but would be utilized in one unit to its maximum eiciency andthe excess only used at lower eccentricity and eiilciency in anotherunit.

Again, small units maintain their higher eiliciencyl much nearer themini um eccentricity. Instead of one unit utilizing o of capacity of thepump and operating at its full capacity, and one using the 20% excessand operating at a slight portion of its capacity, the two units mightbe operated at 50% capacity or stroke, at which the efliciency ofneither has been too greatly reduced,

especially when they are the smaller units of the` transmission.

It is apparent that an innite number of combinations can be obtainedwhen the units are of different sizes, so that each unit of the motormay operate at the greatest eccentricity commensurate with thevolumetric capacity which must be carried and the speed at which themotor is to operate. Such a combination has not been obtained heretoforeand a sacrifice in eiliciency has been necessary for wide range of speedand torque. The pump likewise is of variable delivery and consequentlyfurther adjustment can be effected for given speed and torquecombinations while operating Within an eilicient range.

In some instances it is desirable. to mechanically connect 'the stageunits of the motor so that when one is idle it can be completely disconlAs exemplary of such connection, an overrunning clutch is shown in Fig.6 between the smallest stage unit of the motor and the next adjacentstage unit, these units corresponding to the units 50c and 50h,respectively, of Fig. l and being designated 96' and 95. The larger unit95 is provided at one end With av hub portion 91 having an annulargroove which receives an annular hub portion 98 on the unit 96, forrotatably supporting the adjacent ends of the units with respect to eachother. The annular hub 98 of the unit 96 is provided with a series'ofcircumferentially extending radially opening notches 99, each of whichisof gradually increasing depth radially in a direction away from thedirection of rotation of the unit ssfand deeper than the diameter of therollers at the deeper end. Suitable rollers |00 are disposed in thenotches 99 and extend parallel to the axisf the units. Consequently,whenthe unit 96 is rotating at greater speed than the unit 95,l therollers IM are dis- 1| I posed in the deeper, or trailing, portion ofthe notches 99 and therefore the units are disconnected from drivingrelation and unit 96 rotates freely with respect to unit 95. If,however, more power is required orrthe eccentricity of one of the unitsand its reactance are varied and the unit 95 increases in speed, therollers |00 are rolledtoward the leading or shallow end of the notches99 so as to effect a driving connection between the units 95 and 96.Such an overrunning clutch connection may be provided between two ormore of the units of the motor, as each portion of the pintle, due toits step-down construction, is suiliciently rigid to withstand andsupport the associated unit even though the unit is not supported at theends directly in the casing. In Fig. 8, a lug 95a is shown as providedin the notches 99 for preventing the rollers |00 from wedging tootightly in' the shallow ends of the notches.

Referring next to Fig. 22, there is illustrated a transmission such asabove described, with the exception that the pump is likewisemulti-stage, each unit of the pump being a different size. Both pump andmotor unitsare contained in a simple and compact casing comprising acentral portion |02 corresponding to the portion 2 in Fig. 1. At eache'nd of the central portion |02 are end portions |03 and |04respectively, which are stepped down successively to conform to thedifferent sizes of the pintle portions and cooperating units. 'I'hus thecasing portion |03, adjacent the central portion |02, accommodates alarger diameter pump, this portion being designated |0311. The nextportion |03b accommodates a smaller diameter pump and the third portion|030 accommodates the smallest diameter pump, corresponding to a pumpsuch as illustrated in Fig. 1. The pump units conform in structure tothe motor units illustrated in Fig. 1, as also do the motor units. Forexample, the portions 50a, 50h and 50c of the barrel in Fig. 1

' are accommodated respectively in portions |04a,

|041) and |04c of the casing. The end portions |03 and |04 are closed'attheir opposite ends by suitable end plates |05 and |06 correspondingtothe plates 5 and 6 in Fig. 1, a driving shaft |01 and a driven shaft |08being provided for transmitting power. A suitable port |09 is providedin the casing portion |02 for connection to a sump for replacing slipuid, or the connection illustrated in Figs. 1 and 11 may be used.

In Fig. 21 a blank pintle ||0 illustrates the pintle design. It is seenthat the pintle conforms as near as may be to a parabola C, whichparabola is a function of the load, in proportion to the sectionalmoment of inertia of the pintle. at the point of load application andsection modulus so that the resultant pintle conforms as near as may beto a constant strength beam.

In connection with the pintle, it Will be noted that there are severalconjoint problems to be solved. There is a very fixed relation betweenthe number of plunger cylinders that may be provided and the diameter ofthe associated pintle. Referring to Fig. 9, for example, the larger thediameter or number of cylinders for a given valve bore, the lesscircumferential clearance is provided at the points X, between thecylinders. At the same time, wider space is required between the pintleports for larger cylinders. Consequently, if a larger cylinder withlarger required clearance is provided, this can be obtained only byincreasing the diameter of the bore Y. But an increase in Y must beadded to vthroughout a wider range of operation. All of these and otherfactors are provided for in the structure above described, with theresult that highly eicient and durable wide range transmission iseffected.

As above described, it is desirable to reduce friction between thereactance and the 'piston actuating means to as low a degree asispossible. The cost of .manufacture of and the speeds to be withstood byrotary reactances, if they are to compete with gear transmissions,introduces many problems, especially in high pressure transmissions inwhich the rotary reactance must withstand such terrific stressesand-loads that it is impractical to support it on other than directthrust-anti-friction bearings aligned radially with the load to bereceived.

Al great reduction in diameter can bese-ifeoted `by utilizing stationaryreactances. However,

some reduction in speed of the rotation of thev crosspins can beeifected and if this diameter 'can be suiciently reduced, pro-vision canbe made for withstanding the resultant speed of rotation of the thrustpins about their own axes. This also is accomplished to a considerabledegree by the structure above described.

The multi-stage pump or motor structure herein disclosed is claimed as apump or motor structure per se in my copending application Serial No.31,651, led July 16, 1935 and entitled Multi-stage pump or motor, thesubject matter herein claimed being to'the pump and multistage motorrelation providing the 'transmission mechanism.

Having thus described my invention,

I claim:

1. In a hydraulic device, a rotary pump, a plurality of motor stageunits, each unit comprising a barrel having a set of radial cylinders,plunger assemblies reciprocable therein, independent reactance means forthe assemblies, valve means for the units, means operatively fluidconnecting all the units in parallel and with the pump, clutch meansoperatively interposed between the barrels of adjacent units formechanically connecting one barrel to the other for driving together inone direction of rotation units and having means operatively iiuidconnecting the units and pump, and an overrunning clutch operativelyinterposed between the barrels of adjacent units for mechanicallydrivingly connecting one to the other in one, direction of rotationconsequent upon a predetermined rotational speed of said adjacentbarrels with respect to each other and for drivingly disconnecting thebarrels of said adjacent units consequent upon a reduction, in the speedof one of said barrels relative to the other for permitting freerotation of one barrel relative to the other barrel.

3. In a hydraulic transmission, a pump comprising a rotatable barrel,radial piston an'd cylinder assemblies carried thereby, reactance meansfor the assemblies, a motor comprising a barrel having a plurality ofdifferent diameter portions arranged in the order of size from one 'endto the other, each barrel portion having a circumferential series vofradial cylinders and plunger assemblies reciprocable in the cylindersrespectively, and each barrel portion with its associated cylinders andplunger assemblies providing a motor stage unit of diiferent fluidcapacity, individually adjustable reactances for the units respectively,the said barrel portions having a common axial valve bore, and thecylinders of each barrel portion opening into the valve bore, meansmounting said barrel for rotation vabout the bore axis, a valve pintlefor said barrel, said pintle fitting the said barrel bore, said pintlebeing xedly supported at the end adjacent the largest unit, inlet andoutlet valve ports in the pintle for valving cooperation respectivelywith the cylinders of the corresponding units said pintle having acoaxial portion hydraulically tting the pump barrel and having portsinvalving cooperation with the piston and cylinder assemblies of thepump, duct means ,internally of the pintle connecting the pump to saidpintle ports of the motor in parallel with each other and with the valveports of the pump portion of the pintle in an internal `pressure fluidcircuit.

4.V In a hydraulic transmission, a casing comprising a rigid weightsupporting wall, a valve pintle xedly supported therein and protrudingaxially in each direction therefrom, said pintle having a plurality ofdifferent diameter portions on each protruding portion beginning withthe largest portion adjacent the said wall, and each succeeding portionin the direction toward the end of the pintle being less in diameterthan the preceding portion, a plurality of different fluid capacityrotary radial plunger pump units and a plurality of different capacityrotary radial plungermotor units, said units having coaxial boresfitting about said pintle for valving cooperation therewith, andarranged relative to the pintle for cooperation each with the pintleportion corresponding in size to the capacity of the particular unit,pressure duct means in the pintle operatively connecting all of thepumping units in parallel and with all of the motor units concurrently,discharge duct means in the pintle for said units, an impeller shaft onthe pump coaxial with and extending from the outermost end pump unit,and a torque transmission shaft carried on the motor coaxial therewithand extending from the outermost end motor unit.

5i In a hydraulic transmission, a casing comprising a rigid Weightsupporting Wall, a valve pintle fixedly supported therein and protrudingaxially in each direction therefrom, said pintle having a plurality ofdifferent diameter portions on each protruding portion beginning withthe largest portion adjacent the said wall, and each succeeding portionin the direction toward the end of the pintle being less in diameterthan said large portion, a plurality of different capacity and sizerotary radial plunger pump units at one side of said wall and aplurality of different capacity and size rotary radial plunger motorunits at the other side of said wall, all of said units having axialbores fitting about said pintle and said units being arranged relativeto the pintle for cooperation respectively with thepintle portioncorresponding in size to the capacity of the particular unit, pressureduct means in the pintle operatively connecting all of the pumping unitswith all of the motor units, discharge duct means in the pintle for saidunits, an impeller shaft carried on the outermost end unit of the pumpcoaxial therewith, a torque transmission shaft carried on the outermostend unit of the motor, and the pintle terminating at its ends in spacedrelation to the outer ends of the outermost end units of the pump andthe motor and being supported only at its central portion.

6. In a hydraulic transmission, an independently rotatable rotary pumpmechanism, a rotary fluid motor mechanism, one of said mechanismscomprising a plurality of independently adjustable units, said unitsbeing of different size and different fluid capacity with respect toeach other, the other of said mechanisms comprising at least one unit, avalve member in valving cooperation with and common to all of said unitsand hydrostatically balanced with respect to each unit, means foradjusting each of said plurality of units individually, and said valvemember having means for connecting all of the units in parallel witheach' other in an internal pressure fluid circuit.

7. In a hydraulic transmission, a rotary pump mechanism, a rotaryhydraulic motor mechanism, one of said mechanisms having more than twocoaxial independently adjustable stage units of dierent size andcapacity from each other, the other mechanism having at least one stageunit, means in valving cooperation with all of the units concurrentlyand connecting all of the units in parallel in an internal pressure uidcircuit.

8. In a hydraulic transmission, a rotary pump mechanism, a rotary fluidmotor mechanism. one

of 1 said mechanisms comprising a plurality ofA independently adjustableunits of different size and capacity from each other, the other of saidmechanisms comprising at least one unit, a valve member in valvingcooperation with and common to all of -said units and hydrostaticallybalanced with respect to each unit, means for adjusting each of saidplurality of units individually, and said valve member having means forconnecting all of the units in parallel with each other in an internalpressure fluid circuit, said valve member' terminating endwise shortofthe outer ends of the mechanisms, and shafts on the ends of themechanisms respectively coaxial with respect to the axis of rotationthereof. e

9. The combination with an adjustable rotary fluid pump having an axialimpeller shaft at one end and a multi-stage fluid motor coaxial with thepump and comprising a plurality of independently adjustable stage unitsof different size and capacity from each other and having a commondriven shaft coaxial with the units vand extending from one end of themotor, of a common valve pintle coaxial with the pump and motor andhydrostatically balanced with respect to the' pump and toA each of themotor units and in valving cooperation therewith, and means within thepintle connecting the pump and all motor units in parallel with eachother in a pressure uid circuit.

10. In a hydraulic transmission, a rotary pump mechanism, a rotary fluidmotor mechanism, one of said mechanisms having aplurality ofindependently adjustable stage units of diierent s ize and capacity fromeach other and the other mechanism having atleast one stage unit, meansfor adjusting each one of said plurality of units independently of theothers, v`alve means for all of the units, and means connecting all ofthe units in a pressure uid circuit. l

11. In a hydraulic transmission, the combination of a pump; and a motorconnected in hydraulic circuit therewith, said motor comprising a rotarybarrel having a plurality of separate sets of cylinders, plungerscarried by said cylinders and reciprocable therein, the cylinders ofeach set and their associated plungers constituting a motor unit, thefluid capacities of said motor units differing with respectto eachother, reactance means operatively connected to the plungers of saidunits respectively, and cooperable with the associated plungers foreiecting rotation of the barrel upon reciprocation of the plungers,means mounting said reactance means independently of each other and forindividual adjustment eccentrically with respect to the axis of rotationof the barrel, and means for .selectively and individually adjusting thereactance means of the respective units.

12. In a hydraulic apparatus, ya motor including a fluid intake, aplurality of motor stage units, each unit comprising a barrel having aset of radial cylinders, plunger assemblies reciprocable therein,independent reactance means for the assemblies, valve means forV theunits, means operatively fluid connecting all the units in parallel andto the fluid intake, ciu-tch means operatively interposed between thebarrels of adjacent units for mechanically connecting one barrel to theother for driving together in one direction of rotation consequent upona predetermined rotational speed of one barrel with respect to theother, and for disconnecting the said barrels consequent upon apredetermined rotational speed of one barrel with respect to the other,and

for disconnecting the said barrels consequent v upon a reduction in thespeed of one of said barrelsv relative to the other.

13. In a hydraulic apparatus, a motor including a fluid intake, aplurality of motor stage units, each unit comprising a rotatable barrelhaving a set of radial cylinders, plunger assemblies reciprocabletherein, individually adjustable reactance means for the assembliesrespectively, and valve pintle means for the units and having meansoperatively fluid connecting the units and to the fluid intake, and anoverrunning clutch operatively interposed between the barrels ofadjacent units for mechanically drivingly y connecting one to the otherin one direction of rotation consequent upon a predetermined rotationalspeed of said adjacent barrels with respect to each other and fordrivingly disconnecting the barrels of said adjacent units consequentupon a reduction in the speed of one of said barrels relative to theother for permitting free rotation of one barrel relative to the otherbarrel.

14. In a multi-stage hydraulic motor comprising a plurality of stageunits, each unit comprising an independently rotatable barrel having aset of radial cylinders, plunger assemblies reciprocable thereinrespectively, reactance means for the assemblies, valve means forthe/cylinders, overrunning clutch connecting means interposed betweenadjacent barrels respectively and connecting each barrel to an adjacentbarrel, and being operative to disconnect said barrels and permitgreater rotational speeds of one barrel relative to the other.

15. In a hydraulic apparatus having a pressure fluid inlet, thecombination of a rotary barrel having a plurality of separate sets ofcylinders having valved communication with said inlet, plungers'carriedby said cylinders and reciprocable therein, the cylinders of each setand their associated `plungers constituting a motor unit, the fluidcapacities of said motor units differing with respect .to each other,reactance means operatively connected `to the plungers of said unitsrespectively, and cooperable with the associated plungers for effectingrotation of the barrel upon reciprocation of the plungers, meansmounting said reactance means independently of each other and forindividual adjustment eccentrically with respect to the axis of rotationof the barrel, and means for selectivelyand individually` -adjusting thereactance means of the respective y and a plurality of circumferentiallyspaced radial cylinders opening into said bore, plunger assembliesreciprocable in the cylinders respectively,

Areactance means for the assemblies of each unit,

means mounting said reactance means independently of each other and forindividual adjustment eccentrically with respect to the axis of rotationof the associated barrel, and means for selectively and individuallyadjusting the reactance means of the respective units, said units beingof different diameter fromV each other and arranged coaxially in a rowwith the largest unit at one end of the row and with the remaining unitsin succession in the order of their sizes, and in substantially abuttingend to end relation with only operating clearance therebetween, and acasing comprising different diameter circumferential wall`portionscorresponding to and surrounding the units and having radial `wallportions joining said circumferential wall portions and lying in closelyspaced relation to the ends of the associated units, and a pressure uidcircuit connecting the units 'in parallel..

17. In a hydraulic apparatus, a motor including a fluid intake, a barrelhaving a vplurality of different diameter portions arranged in the orderto' size from 'one end tothe other, each-barrel portion having acircumferential series of radial cylinders and plunger assembliesreciprocable in the cylinders respectively, and each barrel portion withits associated cylinders and plunger assemblies providing a stage unitof different fluid capacity, individually adjustable reactances from theunits respectively, means for selectively and individually adjustingthereactance means of the respective units, the said barrel portions havinga common axial valve bore of different diameter portions correspondingto the associated barrel portion, and the cylinders of each barrelportion opening-into the corresponding Y bore portion, means mountingsaid barrel for portions corresponding to and itting the said barrelbore portions respectively, said pintle being xedly supported at the endadjacent the largest unit, inlet and outlet valve ports in the pintleportions for valving cooperation respectively with the cylinders .of thecorresponding units, means internally of the pintle connecting saidpintle ports, and a torque transmission shaft on and coaxial with theunit remote from the pintle mounting and extending axially therefrom.

18. In a hydraulic apparatus, a motor comprising a plurality ofrotatable stage units, each unit comprising a barrel having an axialbore Vand a plurality of circumferentially spaced radial cylindersopening into said bore, plunger assemblies reciprocable in the cylindersrespectively, individually adjustable reactance means for the plungersof each unit, means for selectively and individually adjusting thereactance means of the respective umts, said units being arranged in arow axially and being coaxial with respect to each other, said unitsbeing diierent diameters and having different uid capacitiesrespectively corresponding to the respective diameterr said umts beingarranged with the largest unit at one end of the row and withtheremaining units inl

